The present invention relates to medical devices and, in particular, to medical devices such as intravenous catheters which include a hollow needle having a sharp distal end or tip for piercing the skin of a patient.
The existence of infectious diseases such as AIDS and hepatitis has highlighted the danger to which medical personnel may be exposed when treating patients by means of catheter devices where a sharp needle tip is used to pierce the skin of a patient. Medical personnel have been infected by physical contact with, or accidental prick by an infected needle (needle-stick).
In order to protect medical personnel against inadvertent needle-stick, a number of solutions have been developed whereby a protective means incorporated within the catheter prevents physical contact with the needle after use and hence against inadvertent needle-stick.
One known device for protecting the needle after use is described in U.S. Pat. No. 5,447,501. In this document, there is described an infusion catheter assembly including a hollow needle having a sharpened distal tip for piercing the skin of a patient. In a ready-for-use position the needle passes through a hole in a rigid front part which houses a resilient member. The resilient member is retained under tension by the needle flank and exerts a force substantially at right angles to the longitudinal direction of the needle. In its retracted position, that is, when the needle tip is moved back through and beyond the hole in the rigid front part the resilient member biases the needle tip laterally to prevent reentry of the needle tip through the hole.
This device is a relatively simple and economic device and is effective to minimize the danger of inadvertent needle stick.
However, since the resilient member is under compression until the device is actually used and since the shelf life of the device is up to three years from manufacture, it has been found advisable to make the resilient member of coiled spring steel in order to avoid the permanent set of the resilient member which would thereby lose its resilience.
It is an aim of the present invention to provide a simple but effective means for protecting the point of a needle forming part of a medical device which incorporates resilient means for deflecting a needle tip in a needle protected position but which avoids the necessity of using coiled spring steel.